buffer: do deprecation warning outside `node_modules`

In addition to `--pending-deprecation`, emit a deprecation warning
for usage of the `Buffer()` constructor for call sites that are outside
of `node_modules`.

The goal of this is to better target developers, rather than
burdening users with an omnipresent and quickly ignored warning.

This implements the result of a TSC meeting discussion
from March 22, 2018.

PR-URL: https://github.com/nodejs/node/pull/19524
Refs: https://github.com/nodejs/node/issues/19079#issuecomment-375121443
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/test/parallel/test-buffer-constructor-node-modules-paths.js b/test/parallel/test-buffer-constructor-node-modules-paths.js
new file mode 100644
index 0000000000..717f783511
--- /dev/null
+++ b/test/parallel/test-buffer-constructor-node-modules-paths.js
@@ -0,0 +1,35 @@
+'use strict';
+
+const child_process = require('child_process');
+const assert = require('assert');
+const common = require('../common');
+
+if (process.env.NODE_PENDING_DEPRECATION)
+  common.skip('test does not work when NODE_PENDING_DEPRECATION is set');
+
+function test(main, callSite, expected) {
+  const { stderr } = child_process.spawnSync(process.execPath, ['-p', `
+  process.mainModule = { filename: ${JSON.stringify(main)} };
+
+  vm.runInNewContext('new Buffer(10)', { Buffer }, {
+    filename: ${JSON.stringify(callSite)}
+  });`], { encoding: 'utf8' });
+  if (expected)
+    assert(stderr.includes('[DEP0005] DeprecationWarning'), stderr);
+  else
+    assert.strictEqual(stderr.trim(), '');
+}
+
+test('/a/node_modules/b.js', '/a/node_modules/x.js', true);
+test('/a/node_modules/b.js', '/a/node_modules/foo/node_modules/x.js', false);
+test('/a/node_modules/foo/node_modules/b.js', '/a/node_modules/x.js', false);
+test('/node_modules/foo/b.js', '/node_modules/foo/node_modules/x.js', false);
+test('/a.js', '/b.js', true);
+test('/a.js', '/node_modules/b.js', false);
+test('c:\\a\\node_modules\\b.js', 'c:\\a\\node_modules\\x.js', true);
+test('c:\\a\\node_modules\\b.js',
+     'c:\\a\\node_modules\\foo\\node_modules\\x.js', false);
+test('c:\\node_modules\\foo\\b.js',
+     'c:\\node_modules\\foo\\node_modules\\x.js', false);
+test('c:\\a.js', 'c:\\b.js', true);
+test('c:\\a.js', 'c:\\node_modules\\b.js', false);